Improvement in valves for direct-acting engines



"UmTED- STATES PATENT QEEICE.v

HENRY A. JAMIESON, OF BROOKLYN, NEW YORK.

. iMPRovEMEN-r |N vA| .vEs Fon DIRECT-ACTING ENGINES.

Specication forming part of Letters Patent No. 155,728, dated October 6,1874; application iiled March 17, 18,74.

To all whom it may concern i Be itv known that I, HENRY A. J AMIEsoN, ofthe city of Brooklyn, in the county of Kings and State of NewYork, haveinvented certain Improvements in' Valves of Direct- Acting Steam Enginesfor Operating Pumps and other purposes, of which the .following is aspecification This invention relates to valves of the descriptionvreferred to in Letters Patent Nos. 144,545 and 146,683, issuedto meAugust 4, 1873, and in which the valve has a compound movement-namely, alongitudinally reciprocating or sliding one and atransversely-oscillating action; also, in which the valve is partlythrown by thedirect pressure of the steam, andinpart, by mechanicalmeans, deriving their motion from the engine. f The` inventionconsistsin an independent sleeve fitted within the steam-chest-for the 'directaction of thesteam, thus insuring a proper relative action of the valveand e11- gine-piston under all conditions of, the latter as regardsspeed, 85e.; also, whereby the steam v Aisl fully exhaustedfrom the-oneend of the valve `in advance of its being Vadmitted to the otherendthereof, and such admission not effected till just before the valvecrosses its center or closes the main ports, and so that incase of avery sudden' or lrapid motionV of the engine-piston, which travelsfaster than the valve, the latter will always be full open or reversedtoward lthe close of the enginestroke, thus 'preventing vthe pistonVstriking the heads of the cylinder. The invention, furthermore,`comprises a certain construction of the valve, whereby theport-controlling portion of it is free to rock without oscillating thepiston-heads of the valve.

, In the accompanying drawing, Figure l represents a verticallongitudinal section mainly on the line fw tc of the steam cylinder andsteam-chest of a pump with my improvements in valves applied. Fig.l2 isatransverse vertical section of the same on the line x a'. Fig. 3 is ahorizontal section of the sleeve in which the'lvalve works with thevalve in the same position as in Figs. l and Z-that is, just as it hascompleted its longitudinal movement to the right and before it is rockedto reverse its action. Fig. 4 is a horizontal section of the sleeve withthe valve removed. section, showing the valve as just having completedits longitudinal movement to the left, but before it is rocked toreverse its action.l Fig. 6, a horizontal section of the same on theline y y. Fig. 7 is a vertical transverse section thereof on the line zz. Figs. 8, 9, and 10 represent a vertical longitudinal section, ahorizontal section, and a transverse section, respectively, of the valveand` sleeve in which it works, showing the valve when about crossing itscenter to the left. Fig. 1l is an under view of the rocking or centralportion lof the valve.' Fig. l2 is a top view of the slottedvalve-shifter; and' Fig. l13, a transverse vertical section of the valveand its sleeve when the valve is in the act of being rocked. v

Similar letters of reference indicate correspending parts. y

A is the steam-cylinder of a pump, and P its piston. C is thesteam-chest, which is a plain casting arranged on the top of thecylinder A, and of cylindrical contour on the inside, but not'requiringany special dress ing as regards the valve surfaces o r portsimmediately controlled by the valve, 'the same' only forming a case, asit were, to receive within it a cylindrical sleeve, D, that is easilydressed, both as regards its interior or valve surface, and as regardsthe squaring-Vor adjustment, by tiling, of` its ports a a andexhaust-opening b, the two former communieating with the passages c c,that lead to opposite ends of the engine-cylinder and the opening bconnecting with vthe general, eX- haust-opening d. This sleeve D isarranged 'to it closely within the chest O, and is in Fig. 5 is avertical longitudinall made to stop short of the heads of thesteamchest, and is furnished with exterior longitudinal grooves f f, oneon either side of its lower portion. These grooves extend a littlebeyond the middle of the length of the sleeve from opposite ends of thelatter, the same opening at their outer ends, respectively, into thespaces intervening between the open ends of the sleeve B and the headsof the chest B. Vents g g are made through the sleeve within the groovesf f, at or near their inner ends, for the purpose of alternatelyadmitting steam to and exhausting steam from the backs of the heads orpistons E E of the valve proper E', which, in addition to having asliding motion, in common with the heads or pistons E E, to control themain ports or openings a c b, has an oscillating or rocking motioniudependently of the pistons E E, to control the vents g g.

This is a great advantage over oscillating the pistons along with thevalve, or thatportion of it which controls the ports, inasmuch as ittakes less power, reduces wear, and provides for the valve more readilyaccommodating itself to its seat.

Such joint and separate actions are obtained by causing the pin h, bywhich the valve is mechanicallyr operated, or a swell around said pin,to enter a yoke, t', of the rod j, which connects the pistons E E, thevalve haust-chamber d, where it gears with or enters a slottedvalve-driver, G, that is rocked at intervals through a lever, k, on theoutside ot' the steam-chest by any suitable link mechanism.

Unlike the slotted driver or drum in my patent No. 144,545, of August 4,1873, the slot Z is not wholly an oblique one, but mainly straight, withone oblique side at each end, on opposite sides to each other, and thegeneral action of the valve is different.

The opposite upper edges of the portion E are each formed with anaperture or cut-away portion, m, to pass the steam, as required, fromthe interior of the valve-space through either set of vents g, alongeither of the grooves f, to the back of either piston E.

The operation is as follows: Supposing the whole valveto be at the endof its stroke in the sleeve D, the lever k is rocked in the reversedirection it is required tov next throw t the valve. This causes the onestraight edge of the slot Z in the driver G to pass freely by the pin 7Lwithout moving it, and afterward, as the oblique extremity of said edgeof the slot comes in contact ywith the pin h, it rocks the valve properE to the right or left, as the case may be, and so brings an underexhaust-cavity, n, in it, in communication, by the one set of vents g,with the one groove f in the sleeve leading to the back of the onepiston E, which occupies a forward or inner position, thus exhaustingthe spent steam used in previously throwing the valve. This exhaustingof the steam from the one end of the valve, before admitting steam tothe other end of it, is an important feature of the action.

A continued motion of the lever 7c in the same direction next causes theend of the slot Z of the driver, which has been brought into contactwith the pin h, to move the whole valve longitudinally in the reversedirection to which it had previously been thrown, until the valve isabout crossing its center, or nearly closing the ports, as representedin Fig. 8, when the rocked valve or portion E establishes communicationthrough the aperture m on its lowest edge, first with one, andultimately with both of the vents g on said side, between thesteam-space of the valve, and by the one longitudinal groove f, the backof that piston E, which is the rear one in motion, This brings steampressure to act directly upon the valve to complete its throw. Duringthis action, the other aperture m-in the opposite edge of the valve belthe action of the vents g, apertures m, and

grooves f.

The herein described mechanical action, combined -with the directpressure of the steam to throw the valve, produces a proper relativeaction of the valve and engine piston under all circumstances ofvariation in speed, and so forth, while, by fully exhausting from theone end of the valve before admitting steam to the opposite end thereof,and admitting steam just before the valve crosses its center to completethe throw of the valve, all liability to accident or breakage,consequent on a reduction of engine-piston resistance, causing thelatter to move at an'unusual rapid rate, and .endangering the vpistonstriking the heads of the cylinder, is avoided, for the reason that,notwithstanding that the piston moves faster than the valve, the latter'is full open or reversed toward the close of the engine-pistons stroke.

I claimf 1. The combination, with a double pistonheaded valve, of thesleeve D, tted within the steam chest, and provided with main l ports aa b, and side openings in communicay tion, by longitudinal grooves ff,with the opposite ends of the chest and interior of thesleeve-substantially as specified.

2. The grooved or slotted oscillating valvedriver Gr, having its slot Zmade straight, with oblique terminations on opposite sides, incombination with the pin h, by which the valve is first rocked, andsubsequently moved longitudinally, essentially as described.

3. The longitudinally sliding and transversely-oscillating valve,constructed of an independent rocking portion or valve proper,

E', and sliding pistons E E,in combination With the yoke i, andoperatingpin h, substantially as specified.

4. Thev longitudinally sliding and transversely-oscillating valve E EE', provided Awith side apertures'm m, in combination with "the vents `gg, the longitudinal grooves f f,

and the main ports a a b, the Whole being `arranged substantially asdescribed, `whereby the valve.

HENRY A. JAMIEsoN,

Witnesses MICHAEL RYAN, FRED. HAYNEs.

